Polymerer3

Question 1

Single screw extruder

Answer 1

Zoner:
1.Solids convering zone(Compaction, kallt transporterar pellets without melting)
2.Transition zone(melting)
3.Metering zone(Pumping, create pressure to pass polymer through die)
RITA! Hopper, Barrel, Screw, Band heaters, Die.

Question 2

Extrusion dies types

Answer 2

Circular, slits, tubular, almost any profile

Question 3

Secondary shaping

Answer 3

A.Fiber spinning(bild snopp:Polymer melt extruder circular die, drawn by parit of take off-rolls)
B.Film Casting(2rutor kula chill-ruta:Polymer melt extruded slit die, rolled through chill roll for cooling
C.Film blowing(kukballong:polymer melt extruded tubular die, air blown through center of tube inflating the melt.)

Question 4

The main units of an injection molding machine

Answer 4

Clamping unit, Mold, Plasticating unit, Injection unit. Principle: inject molten plastic into a cavity, let it cool, and eject the final product.

Question 5

Welding

Answer 5

The line where 2 or more flow fronts meet. Weak spot.

Question 6

Injection molding cycle(main elements of a mould)

Answer 6

1.Mold closes+polymer is injected into the mold cavity
2.Cavity filled+apply pressure until gate is frozen(solid)
3.The screw turns feeding the next shot
4.The mold opens and part is ejected